The overall aim of this core laboratory is to provide well-defined and controlled in vitro systems to each of the four individual projects within the Program to model the in vivo mechanical stresses likely to be involved in modulating the role of osteocytes in bone remodeling. This core will concentrate on providing systems to place osteocytes or osteocyte-like MLO-Y4 cells under well-defined shear stress or equibiaxial radial strain conditions. To accomplish this overall goal the following specific aims have been designed. Specific Aims 1. To provide parallel plate flow systems and technical expertise for subjecting MLO-Y4 cells or primary osteocytes to defined steady or pulsatile laminar flow shear stress levels within the in vivo range, including levels that induce strain sufficient to initiate bone remodeling. 2. To provide equibiaxial strain system and technical expertise for subjecting MLO-Y4 cells or primary osteocytes to define uniform radial strain levels within in vivo range including levels that induce strain sufficient to initiate bone remodeling. 3. To provide consultation on experimental design and technical aspects of individual experiments, coordination of stress regimens across the four projects, as well as help provide interpretation of mechanical stress data.